I and many other 5d mkiii owners have experienced the notorious Error 80, where the camera freezes and the only way to unfreeze it is to take out the battery. It's annoying for photographers but potentially catastrophic for film makers, as the current file is lost. There are numerous reports of Eye-Fi SD cards causing Error 80, so if you've only encountered the error with Eye-Fi cards, please discount those errors as this issue is well known.

My thoughts are that if the Eye-Fi cards are definitely causing problems, then perhaps the type of card is a factor. I've had the error twice, both times with Sandisc Extreme 60mb/s CF cards (I don't think there was an SD card in the slot on either occasion).

As well as participating in the poll, please write below and say if you've had the error, and what brand / size / speed / type of cards have been in the camera at the time.

MickeyTTwo

I've had issues with Transcend 600X cards and Duracell 300X cards so I went and bought myself a 16GB Lexar 1000X UDMA 7 card that cost £100 - and I've still got issues. If I shoot lots of frames in a row and flood the buffer, I'd say 10% of the time the camera struggles to write to the card and sometimes crashes with the dreaded Error 80 message. I'm also seeing far more than normal corrupted images on my cards at the end of a shoot - I never had any at all with a 5D MK II, 60D, 40D and 30D I've owned previously.

Combine this with the fact that Pocket Wizard still don't support the camera for my TTL Flex and Mini radios and I'm seriously hacked off with aspects of the 5d MK III. It's a good job it is so good in other areas like AF performance or I'd be getting rid...

First I've heard of many users having error 80. I had no errors with a CF Card, with 2 cards or with a SD card. I do low lwvel formats of my cards occasionally to find and map out any bad sectors. Its not common to find one on my Lexar or Sandisk cards, but its good practice.

I did not know about the speed issue on SDHC cards so I sent the two I had ordered back and am currently using only the CF, Sandisk Extreme PRO UDMA 6, cards.Maybe I am just lucky because I bought the Eye-Fi 8GB card but have not used it yet.

First I've heard of many users having error 80. I had no errors with a CF Card, with 2 cards or with a SD card. I do low lwvel formats of my cards occasionally to find and map out any bad sectors. Its not common to find one on my Lexar or Sandisk cards, but its good practice.

If you google Error 80 and eye-fi, you'll get plenty of results, but I and other people I know have had the error with high speed CF cards. Among photographers, the issue is not a big deal so isn't talked about much but I know a lot of film makers and there is widespread concern over the issue. You can randomly lose an important clip. At a wedding this is a major problem. So far the people I've talked to have all used just a CF card, but film makers coming from a 5Dii would tend to use CF cards any way, so if enough people respond to the poll I'm hoping that a more conclusive pattern will emerge. I would love to narrow down the error to eye-fi SD cards and CF cards, because at least I would have a system for obtaining 100% reliable footage, not just 99.9%.